Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dang xay » van xay
dang van » hoang van
sach ky » sac ky, sach y, sach ty
dan dan » dang dan, ban dan, dao dan
hieu va » lieu va, hieu qua
cuu tre » cua tre, cau tren, cau treo
am hoc » ad hoc
dan va » doan va, dan ca, ban va
va cuu » va cau, va chu, va huu
va am » va lam, va cam

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((dang xay) OR (((dang van) OR (hang va)))) hoi. hieu va am hoc dan dan va cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky ((dang xay) or (((dang van) OR (hang va)))) hoi. hieu va am hoc dan dan va cuu tre~".
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((dang xay) or (((dang van) OR (hang va)))) hoi. hieu va am hoc dan dan va cuu tre*.